Clarification plant for water purification

ABSTRACT

This clarification plant consists of a circulating reactor in a housing which has a treatment area and a sedimentation area and which is characterized by at least one gas-input element and at least one treatment element which interlock with each other; in the gas input element, the water to be purified is highly enriched with oxygen and subsequently undergoes strong turbulence in the treatment element. The gas input elements and the treatment elements are modularly constructed out of disk-shaped components so that the clarification plant can be scaled as desired. The main purification is done by means of biological reduction processes in micro-organisms which are specifically introduced or cultivated.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a clarification plant for treatingwater with a container which has a water inlet and a water outlet andwhose inner space comprises a treatment area and a sedimentation areaarranged thereunder.

2. Description of the Prior Art

Clarification plants of this type are used for purifying and treatingwater and waste water from industry and households.

It is crucial thereby that as complete a removal as possible of noxioussubstances takes place and that the water has a high oxygen contentafter treatment. The main purification is thereby achieved by means ofbiological degradation processes by micro-organisms which arespecifically introduced to the waste water or are cultivated in theclearing basin.

In production plants there occur organically highly polluted wastewaters which according to the respective statutes for indirectdischarges must be pre-purified to a prescribed COD-limiting value. Thispurification must therefore also take place in constricted spatialconditions in the production plants.

For this purpose, conventional clarification plants are used in whichthe water to be treated is introduced into various basins one after theother. In a first basin there takes place a mechanical pre-clarificationof the water which is then directed into a basin for aeration by oxygen.In this aeration tank, the water is aerated with pure oxygen or with airand hence the oxygen content of the water is increased. In this basin oralso in an adjacent basin the biological purification stage iscompleted, in which, with the aid of micro-organisms, most of thenoxious substances in the water to be treated are degraded. In thisprocess, a great deal of oxygen is consumed by the micro-organisms withthe result that a constant supply of oxygen must be maintained. In orderto prevent agglomeration of the micro-organisms into larger biologicalstructures and the settling of these micro-organisms on the base of thecontainer, the waste water must be constantly agitated. Adjacent to thebiological clearing basin there is a sedimentation area in which surplussuspended matter in the waste water, such as for example agglomerationsof micro-organisms as sewage sludge, are deposited. This area of theclarification plant is designed as a still zone for the treated water.The water which is extracted from the sedimentation basin is extensivelyfree of noxious substances and, after further enrichment with oxygen,can be released into the environment.

The described clarification plant has a very high spatial requirementsince an individual basin is required for the individual functions ofpre-clarification, biological purification and sedimentation and alsooxygen enrichment of the clarified water.

A disadvantage furthermore in the reactors according to the state of theart is that a high input of air is necessary for adequate enrichment ofthe water to be purified with oxygen and that these reactors have a veryhigh energy consumption for the air introduction and the circulation ofthe liquid to be purified.

SUMMARY OF THE INVENTION

It is the object of the present invention to make available aclarification plant which has a high purification capacity with respectto volume and time and also small dimensions and a low energyconsumption.

Furthermore it is the object of the present invention to make availablea clarification plant which can be assembled or dismantled simply andcheaply.

This objective is resolved by the clarification plant according to thepreamble of claim 1 in conjunction with its characterising features.

The clarification plant according to the invention consists solely of ahousing as a liquid container which comprises a treatment area and asedimentation area and in which there is arranged in an appropriatemanner a gas-input element and a treatment element which interlocks withthe latter.

By oxygenating the water in the gas-input element, a buoyancy isproduced within the liquid to be purified, so that the liquid to bepurified is conveyed through the gas-input element and through thetreatment element. In the clarification plant according to the inventiontherefore, mechanical devices for conveying and circulating the water tobe treated are superfluous. This leads to a clear reduction in theinstallation and maintenance costs and also to a noticeably smallerenergy consumption according to the invention. Furthermore byoxygenating the water to be treated directly before turbulence of thewater in the treatment element, a level of saturation of the water withoxygen which up till now was scarcely possible is achieved as a resultof which the achievable biological degradation capacity of theclarification plant according to the invention is very high. Theturbulence of the water in the treatment element leads furthermore to avery fine distribution of the micro-organisms suspended in the wastewater since their agglomeration is greatly impeded. There results alarge interphase interface between the micro-organisms and the noxioussubstance substratum of the water to be treated, resulting in theattainment of a very high biological rate of degradation of the noxioussubstances.

In the clarification plant according to the invention a circulatingreactor is used because of the direction of flow of the water to betreated from the inlet of the gas-input element to the outlet of thetreatment element and back around these elements to the inlet of thegas-input element. There takes place thereby the aerobic biologicalpurification of the water within the treatment element while the returnflow, which takes place outwith the treatment elements, leads inanaerobic conditions amongst other things to a reduction in nitrates inthe water and to suppression of the formation of chlamydobacteriales. Inthe clarification plant according to the invention, aerobic andanaerobic clearing stages are initiated consequently one after anotherin a cyclical fashion in a simple manner in the same housing. Theduration of the respective clearing stage can be influenced by thevolume of the treatment elements and by the circulation speed producedby the oxygenation of the water.

By means of particularly intensive air introduction via the gas-inputelement in periodic pulses the buoyancy and hence the circulation speedof the water to be treated can be increased step-wise and also with astrong admission of air a purification operation can be achieved in thegas-input element and the treatment element.

Advantageous further developments of he clarification plant according tothe invention are given in the dependent claims.

Particularly simple flow conditions occur when the gas-input element andthe treatment element are arranged vertically and, as a result, thebuoyancy produced by oxygenation of the water to be treated is exploitedto the maximum.

The geometry, i.e. height, width or depth of the clarification plantaccording to the invention can hence be chosen, while maintaining thedesired volumes of individual clarification plant components andmaintaining the desired length of stay in the treatment element, in sucha way that several gas-input elements are used which are connected viadistributors to any number of treatment elements respectively.Alternatively, several arrangements of gas-input elements and treatmentelements can also be arranged one above the other in series. Hence, anydesired treatment volume can be realised in any dimension in a simplemanner.

In an advantageous manner there is arranged beneath the gas-inputelement a sedimentation area which is provided with a bio-mass outlet sothat the produced and deposited bio-mass which is no longer required forthe further purification process can be removed periodically from theclarification plant according to the invention via the bio-mass outlet.

It is particularly advantageous if a rest zone is arranged directly infront of the water outlet and separated from the circulating liquid by adividing wall, said rest zone being fitted with canted plates so that afurther sedimentation zone occurs there for removing residues ofsuspended particles in the purified water.

The flow velocity within the gas-input element and the treatment elementcan also be influenced via a submerged pump, the suction side of whichis connected above the sedimentation area and the discharge side ofwhich is connected to the inlet of the gas-input element. Furthermore,it is possible within the gas-input element or the treatment element toinstall agitation elements, worm-like elements or rotor blades which areactuated from outside and take care of additional conveyance oragitation of the water to be treated.

Monitoring of the filling height of the clarification plant according tothe invention with water to be treated can take place by means of afloat switch.

For final oxidation of the treated water which has been removed from thewater outlet a trickling section may adjoin the water outlet, into whichtrickling section the purified water can be enriched additionally withoxygen in order to produce the prescribed oxygen content forintroduction into the sewage system or into the ecosphere.

The gas-input element, the treatment element and the trickling elementof the clarification plant according to the invention can be composed atleast partly from identical or similar disc-shaped components so thatthe clarification plant can be scaled as desired. As a result, theclarification plant according to the invention can also be usedeconomically for the smallest amounts of waste water. Accommodation toan altered requirement can also take place subsequently since theassembly and dismantling of the gas-input element and the treatmentelement are very simple. On the basis of the clarification plantaccording to the invention having the capacity to be scaled as desired,the costs for carrying out the waste water clarification can alsocorrespond respectively to the requirement and be minimised.

A particularly simple and cost-effective construction of the gas-inputelement, the treatment element end also the trickling element resultsfrom using components which have an outer ring channel and an inner ringchannel and also several webs extending between these channels. The webscan open out thereby into the outer ring and/or the inner ring channelso that a channel system occurs via which for example substances such asnutrient solutions, gases or even enzymes can be added. Such a supplymeans is especially simple if the elements are made of ceramic and theceramic has a porous structure. Thus the gas-input element consists, inan advantageous manner, of components of this type which have anair-permeable, porous structure so that very fine air bubbles can beintroduced into the water to be treated via the outer ring channel andthe webs. By means of this particular structure, there results a degreeof oxygen enrichment in the water to be treated of a level scarcelyattainable using conventional measures. This increases the buoyancy fromthe gas-input element to the treatment element and in addition improvesthe effectiveness of the biological purification in the followingaerobic treatment stage. In a similar manner, the components from whichthe treatment element is formed can have appropriately formed webs whichlead to a specific, turbulent agitation of the water to be treated. As aresult, the agglomeration of the micro-organisms to larger complexes isprevented and an interface size is achieved between the micro-organismsand the water to be treated which is not achieved with the conventionaltechnique. This also considerably improves the biological purificationeffect within the treatment element. The trickling element can likewisebe constructed from components with correspondingly formed webs.

A further advantageous embodiment of the components has a duct in thecentre of the inner ring channel which can receive a central shaftextending in the axis of the component. With individual components, thecentral shaft can then be connected to the webs so that the webs in theform of agitation elements, worm elements or rotor blades can be rotatedto produce a current. The driving force of the central shaft resultsthereby from outside. This represents a particularly simple opportunityto monitor the flow velocity in individual treatment elementsindividually and independently from one another.

The periodic introduction described above of additional quantities ofgases into the liquid to be treated, in order to produce an additionaldriving force or a purification effect within the clarification plantaccording to the invention, can also be achieved via an additionalcompressed air pipe which is connected to the gas-input element andintroduces in pulses large quantities of compressed air into the liquidto be treated via corresponding components which hare especially largepores.

BRIEF DESCRIPTION OF THE DRAWINGS

A few embodiments, given by way of example, of the clarification plantaccording to the invention are described subsequently.

FIG. 1 shows a clarification plant according to the invention;

FIG. 2 shows a section through a clarification plant according to theinvention;

FIG. 3 shows an arrangement according to the invention of gas-inputelements and treatment elements;

FIG. 4 shows the connection between the gas-input element and fourtreatment elements;

FIG. 5 shows a further clarification plant according to the invention;

FIG. 6 shows a further clarification plant according to the invention;

FIG. 7 shows an arrangement according to the invention of treatmentelements and gas-input elements;

FIGS. 8a and 8b show two components with and without a central shaftduct;

FIGS. 9a and 9b show a gas-input element in cross-section and also thecourse of the oxygen supply in two variants;

FIG. 10 shows a component with a central shaft duct;

FIG. 11 shows a rotor element and

FIG. 12 shows an element for the supply of oxygen in pulses.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 shows a clarification plant according to the invention. A waterinlet 2 is installed on a housing 1 for supplying water to be treatedand there is also a water outlet 3 as a clarified outlet. Furthermore,in the housing 1 and vertically one above the other there are arrangedone gas-input element 4 and a plurality of treatment elements 5 whichare connected via a distributor 7 with one another. Beneath thegas-input element 4 a sedimentation area is located for the depositionof surplus bio-mass. The area above the sedimentation area 8 isdesignated as a treatment area 9.

The gas-input element 4 is connected to a gas supply line 6 via whichthe oxygen or atmospheric air required for oxygenating the water to betreated are supplied to the gas-input element 4.

In order to operate the clarification plant according to the inventionwater to be treated is supplied via the water inlet 2 up to a levelestablished via a float switch 13. Next, oxygen-containing air is blowninto the gas-input element 4 via the gas supply line so that the liquidlocated therein experiences a buoyancy and is moved by the gas-inputelement 4 to the treatment element 5 and right through this. By means ofthis flow, water is sucked into the treatment area directly above thesedimentation area and is likewise forced into the treatment elements 5by the gas-input element 6 and the distributor.

In the gas-input element 6, the water to be treated is greatly enrichedwith oxygen so that a biological, aerobic reduction of the noxioussubstances is performed in the treatment elements 5. In these treatmentelements, the water is agitated very powerfully, so that themicro-organisms located there do not agglomerate into large complexes.Consequently, the contact surface between the micro-organisms and thewater to be treated is kept high, as a result of which the capacity fordegradation of the noxious substances is greatly increased.

After passing through the treatment elements, the oxygen in the water tobe treated is extensively consumed by the micro-organisms. The water tobe treated flows thus in anaerobic conditions along the outside of thetreatment elements 5 back into the likewise anaerobic sedimentation area8. In these anaerobic areas the water is purified for example by theremoval of nitrogen compounds in addition by anaerobically livingmicro-organisms. Furthermore, there is suppression here of the undesiredformation of chlamydobacteriales

During reduction of noxious substances the bio-mass of themicro-organisms is increased so that the surplus bio-mass is nowdeposited in the sedimentation area 8. From there it can be removed asdesired via a bio-mass outlet 24 as sewage sludge.

The treated water flows partly back into the gas-input element 4 and thetreatment elements, and there it is purified further or mixed withfreshly supplied water to be treated or it is removed via the clarifiedoutlet 3 as treated water. Next, it can be enriched further with oxygenvia a trickling section.

FIG. 2 shows a clarification plant according to the invention with fourtreatment elements in total. The design of this clarification plantaccording to the invention is essentially identical to the clarificationplant shown in FIG. 1. It can also be seen very clearly that the fourtreatment elements 5 are connected via a funnel-shaped distributor tothe gas-input element 4. The gas-input element consists of fivedisc-shaped components which on their periphery have in total fourrecesses respectively which are offset to one another by an angle of 90°and orientated in the direction of flow of the water and via whichcomponents oxygen is supplied under pressure to the individualcomponents of the gas supply line 6.

The four treatment elements 5 are constructed from disc-shapedcomponents which have an outer ring channel 15 and an inner channel 16and also webs 17 extending radially between these channels. These webs17 cause turbulence in the water to be treated.

On the basis of the selected modular principle and the use ofmodule-like components, assembly, dismantling and alteration of theclarification plant according to the invention is possible at any timewith the smallest demand on labour and cost.

FIG. 3 shows an arrangement of gas-input elements 4, distributors 7 andtreatment elements 5 with in total six gas-input elements 4 andtwenty-four treatment elements 5. A unit of this type is also suitablefor purifying large quantities of water.

FIG. 4 shows in section, however, a gas-input element 4 which isconstructed from in total four disc-shaped elements 14 and which isflanged by its outlet 25 to a distributor 7. The distributor opens intoaltogether four treatment elements 5. It is achieved by means of thisarrangement that the liquid which has been oxygenated in a gas-inputelement 4 is then conveyed to in total four treatment elements 5.

FIG. 5 shows a clarification plant according to the invention, which isconstructed similarly to the clarification plant shown in FIG. 1. Thesame parts of the clarification plant are thereby designated with thesame reference numbers. In this clarification plant, the outlet from thetreatments elements 5 to the clarified outlet 3 is divided by a wall 10so that an additional still zone occurs immediately in front of theclarified outlet 3 between the housing 1 and the wall 10. At the wall 10and the housing 1 in this still zone, plates can be inserted which aredirected obliquely upwards and are for example at an angle of 30° to thewall 10 so that any residual suspended matter, which is still in thetreated water, is deposited on these plates. Therefore, there results anadditional residual sedimentation area directly in front of theclarification outlet 3.

Furthermore the inlet of the gas-input element 4 is connected to thedischarge side of a suction pump 12, the suction side of which lies inthe intermediate area between the sedimentation area 8 and the treatmentarea 9. By means of the submerged pump 12, the flow velocity of thewater to be treated can be controlled in addition by the gas-inputelement 4 and the treatment elements 5 as a result of which the degreeof oxygenation of the water in the gas-input element 4 may likewise beinfluenced.

FIG. 6 shows a further example of a clarification plant according to theinvention in which operating elements, which are accessible fromoutside, are arranged above the housing 1 and are accessible via aladder 30. The housing 1 comprises here a multiplicity of treatmentelements 5 which are interlocked with gas-input elements 4 at theirrespective lower end. Several of the units of gas-input element 4 andtreatment element 5 are thereby arranged one above the other and areconnected to one another in such a manner that the water to be purifiedflows from the respective lower treatment element 5 through a gas-inputelement 4 into the next treatment element 5. The gas-input element 4 hasa further connection which is connected to the waste water inlet pipe 2.The waste water is directed through this pipe 2 directly into the lowestgas-input element 4 where it is enriched with oxygen for a first time.The supply of waste water is monitored via a float switch 13.

In this clarification plant also, the water now enriched with oxygenflows upwards through the treatment element 5, in which biologicalclarification takes place. At the end of the first treatment element,the oxygen content of the water is extensively consumed by themicro-organisms so that the now already extensively pre-cleaned water isreplenished for a second time in a gas input element 4 with oxygen.Next, it runs through an upper treatment element 5. At the end of thepurification, the water emerges at the upper end of the upper treatmentelement 5 and flows along the outer side of the treatment element 5downwards into the sedimentation area 8. In this sedimentation area 8,the surplus of micro-organisms is then deposited and may be removed whenrequired by a submerged pump 28 and via a pipe 35 and also via thebio-mass outlet 24. The pump 28 can for example by actuated from abovethe housing 1 via a chain 36 extending through the housing 1. Betweenthe sewage sludge pipe 35 and the waste water supply line 2 there existsa connecting pipe 37, via which the waste water can be injectedcontinuously or from time to time with sewage sludge and hence withliving micro-organisms.

The unit shown in FIG. 6 is particularly suitable for purifying, in ascomplete a manner as possible, highly polluted waste water in a smallspace and with a small expenditure of energy. Because of the stackedarrangement of the units of gas-input elements 4 and treatment elements5 a very long purification section is achieved.

During purification of the waste water heat arises because of themetabolism of the micro-organisms so that the temperature of the wastewater along the treatment elements changes. With the help of heatexchangers which likewise consist of individual components, thetemperature can indeed be regulated in such a way that, everywhere inthe treatment elements, the optimal temperatures can be extensivelymaintained for the desired micro-organisms which are specific to thenoxious substances.

FIG. 7 shows an arrangement according to the invention of treatmentelements 5 and gas-input elements 4. Alternatively, a gas-input element4 and a treatment element 5 may be interlocked with one anotherrespectively. As a result, a very long column results which consists ofan alternating series of gas-input elements 4 and treatment elements 5.The gas-input elements 4 consist of a series of disc-shaped components14. The lowest gas-input element 4 consists of six components 14 whilethe further gas-input elements of the column consist of four componentsrespectively. Four of the components of the gas-input elements 4 areconnected respectively with a gas supply line 6. In the lowest gas-inputelement 4 a component is connected to a supply line 31 for waste waterand a further component 14 is connected to a supply line 32 for sewagesludge. This lowest gas-input element 4 has a flange 27, which isconnected to a second compressed gas supply line, at its entrance.

Via the pipe 31, waste water is fed into the interior of the gas-inputelement via one of the components 14 of the lowest gas-input element 4.Via the pipe 32, sewage sludge is added to the waste water via a furthercomponent 14 of the lowest gas-input element 4 in order to inject thesaid waste water with living micro-organisms for biologicalpurification.

The remaining four components 14 of the gas-input element 4 serve tooxygenate the waste water by supplying atmospheric compressed air orpure oxygen via the gas supply line 6.

This gas supply line 6 is likewise connected to the components 14 of thefurther gas-input elements 4 and provides for periodic aeration of thewaste water along the column.

In order to clean the column of gas-input elements 4 and treatmentelements 5 when required, the lowest gas-input element 4 is connected toa second compressed air supply line 11, via which the large quantitiesof air may be injected. Such large quantities of air produce anadditional buoyancy of the liquid located in the column and lead to agood mechanical cleaning of the column.

The arrangement shown in FIG. 7 can be provided with a sedimentationarea and a housing and represents a device according to the inventionwhich is distinguished by a high purification capacity in the smallestspace.

FIGS. 8a and 8b show two disc-shaped components as they are used for theconstruction of gas-input elements or treatment elements as for examplein FIGS. 1 and 2. FIG. 8a shows a component 14 with an outer ringchannel 15 and an inner ring channel 16 and also webs 17 extendingradially between these channels. Furthermore, the component 14 in thisexample has in total six axial recesses 18, via which several components14 stacked one above the other may be connected together or via whichmaterials may be exchanged between several components 14 stacked oneabove the other. Through these axial recesses 18, a liquid with enzymescan be supplied to each component 14 for example along a column ofcomponents 14 according to the invention or a gas can be supplied intothe outer ring channels 15 connected to the axial recesses 18 anddirected from there into the webs 17 connected to the outer ringchannels. If the webs 17 are made of a porous, for example ceramicmaterial, then in this way large quantities of gases can be compressedin a very fine distribution into a liquid flowing within the component14.

This possibility is made use of by using the components shown in FIG. 8afor constructing the gas-input elements 4 of FIG. 1. The gas supply line6 is then connected at one end to one of the axial recesses 18 of acomponent stack while the remaining free openings, of the axial recesses18 are closed off. If oxygen or atmospheric air is now introduced viathe gas supply line 6 into the axial recesses then this air isdistributed via the outer ring channel 15 to the webs 17 and iscompressed through the porous ceramic wall of the webs 17 into the waterto be treated.

FIG. 8b shows a similar component as in FIG. 8a, the inner ring channel16 having a duct 19 which can receive a central shaft.

FIG. 9a shows the construction of a gas-input element made fromcomponents 14 shown in FIG. 8b. The components 14 are stacked one abovethe other and screwed together between the individual axial recesses 18via screw connections 26. The axial recesses 18 of the individualcomponents 14 are connected to one another while their open ends areclosed off.

The gas-input element 4 is provided at both of its ends with one flange27 respectively so that said element 4 can be connected at its inlet forexample with a submerged pump 12 and at its outlet with a distributor 7or also be directly connected to a treatment element 5.

FIG. 9b shows two of the many options for gas flow control within thegas-input element 4. For this purpose, the components 14 are providedbetween the individual axial recesses 18 and between the axial recessesand the outer ring channel 15 with breakable seals which can be easilydestroyed to produce a specific direction of flow. It is possibleconsequently to realise within a gas-input element of this type a largenumber of possible ways to control the gas flow, two of which are shownin FIG. 9b. In the left-hand representation of FIG. 9b the gas issupplied respectively from one axial recess 18 via the webs 17 and theouter ring channels 15 of the opposite recess 18. There the gas withinthe axial recess 18 is directed to the next component 14 where a sideexchange takes place in turn. Consequently, a gas flow control accordingto the reverse flow principle occurs through the gas-input element. Inthe right-hand representation of FIG. 9b, the gas is supplied via anaxial recess 18 simultaneously to all the components 14 of the gas-inputelement 4 and directed parallel to the axial recesses 18 locatedopposite.

An arrangement of components 14 of this type can also be chosen for theconstruction of treatment elements 5; the channel system of thecomponents 14 having the capacity to be used for example for supplyingthe enzymes or nutrient solutions to the liquid to be treated.

With a gas-input element as shown in FIG. 9a, an O₂ introduction of over34 mg O₂ /l was achieved. This value lies around a multiple of fourabove the value of 8 mg O₂ /l which can be achieved by conventionalmembrane technology.

Examinations of a reactor whose gas-input elements and whose treatmentelements are constructed from the mentioned components revealed that,with a degrading level of 90%, the treatment element has a purificationcapacity of approximately 80 kg COD/m³ /day. This value is double theloading rate which is achieved in laboratory experiments using aconventional bubble column reactor. Also the COD-sludge loadingL_(drysubs). achieves with approximately 11 kg COD/kg dry subs./dayroughly double the value of a bubble column reactor. A comparison of thebacteria agglomerations shows that the agglomerates are smaller with aclarification plant according to the invention than with a bubble columnreactor or with conventional purification units, so that a greaterinterface results between the micro-organisms and the water to betreated with respect to the quantity of micro-organisms than withconventional clarification technology.

FIG. 10 shows a further component 14 according to the invention, theinner ring 16 of which is provided with a duct 19 for a central shaft.The webs are thereby configured very thinly and serve substantially formounting the inner ring 16. Components 14 of this type can be used forexample for bearing a central shaft on the respective ends of thetreatment elements 5.

FIG. 11 shows a rotor element which has a central shaft 21 and alsofreely rotating webs 22 which are secured to the central shaft 21 andused as rotor blades. With a rotor element of this type, currents can beproduced in liquids within the treatment or gas-input elements. Hence,especially the flow velocity can be controlled in each individualtreatment element independently of the other treatment elements.

FIG. 12 shows an injection element as it may be used to inject in pulseslarge quantities of gases for example into the gas-input element 4. Thegas is again directed via axial recesses 18 into the outer channel 15and from there injected via openings 23 into the liquid flowing withinthe injection element. There are shown in total three different formsfor openings 23, namely slots, round openings and also openingsprojecting nozzle-like and radially from the outer ring channel 15 intothe inner volume. Components of this type can be used especially foradmitting large quantities of gas to increase the buoyancy of the liquidor for thorough cleaning of the gas-input elements 4 and the treatmentelements 5.

There is furthermore shown in FIG. 12 that the outer ring channel can beinterrupted by seals 20 so that a plurality of gases and liquids canalso be directed in the packing direction of the components via theaxial recesses 18, independently of one another. The various currentsare shown by arrows. This component can be connected to each of thedescribed components.

What is claimed is:
 1. Clarification plant for treating water with acontainer which has a water inlet and a water outlet and whose innerspace comprises a treatment area and a sedimentation area arrangedthereunder; there being arranged in the treatment area at least onegas-input element for oxygenation of the water and at least onetreatment element, wherein the at least one gas-input element and the atleast one treatment element are arranged one above the other in acolumn-like shape and between these and the wall of the container lies apart of the treatment area; the gas-input element is provided with atleast one water inlet and at least one water outlet and has severaldisc-shaped components which are connected together into a stack throughwhich the water moves; the water inlet of at least one gas-input elementbeing connected to the sedimentation area, and the at least onetreatment element is provided with an inlet and an outlet and the wateroutlet of the gas-input element is interlocked with the inlet of atleast one treatment element; the water emerging from the gas-inputelement being agitated specifically and thoroughly mixed during flowthrough the treatment element and after emerging from the treatmentelement flowing between its outer side and the wall of the container tothe sedimentation area.
 2. Clarification plant according to claim 1,wherein the outlet of the treatment element or one of the treatmentelements is connected to the inlet of a further gas-input element towhich a further treatment element is attached.
 3. Clarification plantaccording to claim 2, wherein several gas input elements and treatmentelements are arranged to form a column.
 4. Clarification plant accordingto claim 1, wherein each gas-input element is connected to severaltreatment elements via a distributor.
 5. Clarification plant accordingto claim 1, wherein the water outlet is separated from the treatmentarea by a wall to form a separated part; the separated part near thesedimentation area interconnecting with the treatment and/or thesedimentation area.
 6. Clarification plant according to claim 5, whereinin the separated part, the container and/or the wall are provided withplates extending upwards.
 7. Clarification plant according to claim 1,wherein the inlet of the gas-input element is connected to the dischargeside of a submerged pump, which is arranged in the container and whosesuction connection piece is located between the sedimentation area andthe treatment area.
 8. Clarification plant according to claim 1, whereinthe gas-input element and/or the treatment element are formed at leastin part from a stack of interlocking, disc-shaped components which areconnected to one another and are identical or similar to one another. 9.Clarification plant according to claim 8, wherein the components have atleast one outer ring channel and inner ring channel and several websrespectively which extend radially between the outer ring channel andthe inner ring channel.
 10. Clarification plant according to claim 9,wherein the webs open into the outer ring channel and/or the inner ringchannel.
 11. Clarification plant according to claim 9, wherein thecomponents have at least one axially extending recess outwith the outerring channel.
 12. Clarification plant according to claim 1, wherein thechannels, the at least one axially extending recess and the webs areseparated from one another by removable or by breakable dividing wallsor are connected to one another by removing or breaking through thedividing walls so that only a predetermined selection of channels,recesses and webs interconnect with one another.
 13. Clarification plantaccording to claim 9, wherein the webs have a porous, air-permeablestructure.
 14. Clarification plant according to claim 9, wherein thecomponents have at least partly in the center of the inner ring channela duct for receiving a central shaft extending along the stack. 15.Clarification plant according to claim 14, wherein on the central shaftthere are attached in one part of the components, agitation elements,worm elements or rotor blades for producing a current which extends fromthe central shaft outwards into the intermediate space between the innerand the outer ring channel.